San Francisco is truly the test bed for alternative tech-focused transportation. And on Tuesday, folks in the Bay Area will have access to yet another option: SideCar, a mobile app that will offer real time ride sharing.

The idea behind the app is to connect drivers who want to make a little extra money, with passengers that are looking for an alternative to driving, biking or public transportation in real time. Picture what Uber is trying to do with an on demand car service but for regular car owners. Ride sharing company Zimride recently started offering something similar through its Lyft mobile app. “It’s a rethink of transportation,” Sunil Paul, SideCar’s CEO and investor through Spring Ventures, tells me in an interview.

The app is launching to the public today, and has been in use in beta since February. So far 10,000 rides have been shared over the past few months, says Paul.

The technology came from a team in Michigan, and Paul says he himself holds a patent for using smart phones for coordinating transportation. The company was seed funded from a long list of well known investors including Huron River Ventures, SV Angel, Lerer Ventures, First Step Fund, Jeff Clarke, Lisa Gansky (who wrote The Mesh), Robert Goldberg, Jared Kopf, Konstantin Othmer, Mark Pincus, Martin Roscheisen (former Nanosolar CEO), Josh Silverman, and Thomas Varghese.

An interesting hitch is that to avoid having the driver be classified as running a commercial service (and thereby violating his/her insurance policy) SideCar has no formal payment plan in place for rides. The system will show the average donation paid for a ride, but the payment itself is voluntary. While that might seem a little weird, I think that most riders will just default to the average — the mentality behind tipping works the same way. And because the system runs on credit cards, that avoids the awkward exchange of cash.

A big focus for the team in the beta phase has been making sure its drivers and riders feel safe and secure. The achilles heel of the collaborative consumption movement is security, from Airbnb’s security scare last year, to Hi-Gear shutting down its luxury car sharing service after being targeted by thieves.

Paul says that both drivers and riders are screened and vetted. The passengers need to have already entered a valid credit card, and drivers need to have a current drivers license, are interviewed and background checks are conducted. The cars being used in the system also can’t be too old and have to have four doors.

SideCar is an example of two emerging trends. First, the CleanWeb, or using information technology to manage resources and infrastructure. Paul coined this phrase and it’s the basis for his investing thesis. SideCar can reduce the amount of cars on roads (and fuel burned) by providing alternative transportation options. Second, the collaborative consumption movement, or using mobile and social to share “stuff” from apartments (Airbnb) to cars (RelayRides).

Other alternative startups available in the Bay Area include Uber, peer-to-peer car sharing companies RelayRides and Getaround, electric scooter sharing with Scoot Networks, Google-style commuter buses with RidePal and old-school car sharing companies Zipcar and CityCar Share. Paul previously was incubating a peer-to-peer ride sharing company called Spride Share, but decided to shelve that company because he says he decided he didn’t like the business model.